Audion.



A. MoL. NIGOLSON.

AUDION.

APPLICATION FILED JUNE 6, 1914.

Patented Mar. 2, 1915.

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1. NDER MOLEAN NI COLSON, 0F TARRYTOWN, NEW YORK, ASSIGNOR '10 WESTERN ELECTRIC COMPANY, OF NEW YORK, N. Y., A CORPORATION OF ILLINOI AUDION.

To all whom it may concern:

Be it known that I, ALEXANDER MOLEAN NIooLsoN, a subject of the King of Great Britain, residing at Tarrytown, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Audions, of which the following is a full, clear, concise, and exact description.

This invention relates to an audion of the high-current outputtype, and its object is to increase the efficiency of such audions.

One of the factors determining the efficiency of audions is the strength of the electric field between the input electrode and the It has been discovered that by providing an input electrode having a large surface, and by placing the filament in close relation to such surface, an extremely strong electric field is produced, resulting in-corresponclingly increased eliiciency.

The present invention contemplates an input electrode in the form of 'a shell, preferably cylindrical in form, having the audion filament spirally arranged in close PI'OXlI'II' ity to that surface of the shell which is ad- I jacent to the output electrode. Furthermore, in accordance with this invention, the output electrode is of a form similar to that of the input electrode and is arranged concentric'ally therewith. In case the inner one of these two shells constitutes the input electrode, the filament is coiled about said inner shell from end to end thereof. The filament may be maintained out of electrical contact with the shell by a suitable dielectric.

This invention may be more readily understood by reference to the accompanying drawing, showing in perspective an audion embodying the invention.

Referring to the drawing, the input electrode is shown as consisting of a c lindrical shell- 1. The filament 2 is woun spirally Specification of Letters Patent. Application filed. June 6,1914. Serial No. 843,505.

Patented Mar. 2, 1915.

about the cylindrical shell 1. The surface of the shell 1 may be provided with a spiral groove 3 to receive the coils of the filament. The plate 1 may be covered with a dielectric coating, such as nickelous oxid, at the points of contact of the filament therewith.

The output electrode is shown in the form of a cylindrical shell 4, outside of and concentric with the shell 1.

In the structure above described, it will be noted that the input electrode and output electrode each has a large surface and that said surfaces are in parallel relation to each other. This, it has been discovered, is conducive to an efiicient high-current output. As usual, the filament, the input electrode and the output electrode are inclosed in an evacuated bulb 5, the leading-in wires to said elements being sealed in the bulb.

What is claimed is:

1. An audion having an input and an output electrode consisting of concentric shells, and having a filament arranged close to the input electrode at the side toward the output trode which is adjacent to the output electrode.

3! An audion having an input electrode in the form of a cylindrical shell, a filament wound about said shell, and an output electrode in the form of a cylindrical shell concentric with said first-mentioned shell.

In witness whereof, I hereunto subscribe my name this 3 day of June A. D., 1914.

ALEXANDER McLEANNIGOLSON. 

